Toothbrush

ABSTRACT

A toothbrush comprising a head ( 10 ) carrying a group of bristles ( 20 ); an elongated handle ( 30 ), having a free end ( 31 ) and an opposite end ( 32 ); and a neck ( 40 ), connecting the opposite end ( 32 ) of the handle ( 30 ) to the head ( 10 ). Said handle ( 30 ) presents, on its front face ( 30   a ) and at the opposite end ( 32 ), a first shoulder ( 33 ) defining a thumb supporting front region ( 33   a ); and, on its rear face ( 30   b ) and spaced from the free end ( 31 ), a second shoulder ( 34 ) having opposite sides for supporting the little finger and the ring finger, respectively. The first and the second shoulders ( 33, 34 ) are used when the toothbrush is gripped with the bristles ( 20 ) turned to the user. The handle ( 30 ) has a cross section contour that increases generally from the thumb supporting region ( 33   a ), close to the first shoulder ( 33 ), to the second shoulder ( 34 ). The rear face ( 30   b ) of the handle ( 30 ) is further provided with a thumb supporting rear region ( 35   a ), to be used when the toothbrush is gripped with the bristles ( 20 ) turned away from the user.

FIELD OF THE INVENTION

The present invention refers, generally, to toothbrushes and, particularly, to a construction for a toothbrush handle having improved ergonomic characteristics, which increase the comfort of the user during the brushing operation of the teeth.

BACKGROUND OF THE INVENTION

Toothbrushes should be designed to assure a firm and safe grip of the handle by the user and, consequently, an efficient and comfortable brushing operation of the different parts and surfaces of the dental arcades. In order to allow the user to reach said different parts of the mouth and to brush different surfaces of the teeth, according to different brushing movements, the toothbrushes should have the handle thereof designed for assuring an adequate grip in different operational conditions of rotation of the handle in relation to the user's hand.

Aiming at obtaining a construction that guarantees a safe and comfortable grip in different operational conditions defined by the user himself during the brushing operation, different toothbrush handles have been proposed, some handles presenting a circular or polygonal cross section, which is maintained substantially constant along the length of said handle. In other cases, the cross section of the handle suffers dimensional alterations along the length thereof, particularly with regard to its height, in order to form shoulders, which help the axial locking of the handle in relation to the user's hand. In these cases, the rotational locking of the toothbrush is obtained by the cross section of the handle, which is shaped to make difficult the involuntary rotation of the handle around its longitudinal axis. These solutions with a polygonal cross section usually lead to toothbrushes that are not comfortable to grip. Moreover, in other cases, together with variations in the dimensions of the cross section along the length of the handle, the latter is further provided with inserts made of an antiskid elastomeric material, having smooth or irregular surfaces.

These prior art constructions, among which is found the construction disclosed in patent application PCT/US96/12944 (WO97/07706), have the object of providing toothbrushes which are easy to be held and controlled, giving a better control of the brushing movements in the different positions chosen by the user. In the prior art document cited above, the proposed handle comprises: a front shoulder portion, which is preferably formed of an elastomeric insert; a neck, connecting the shoulder portion to the head of the toothbrush; a free end portion with an increased cross section; and a waist provided between the shoulder portion and the free end portion and presenting a width and height slightly inferior to those of the shoulder portion. It is also mentioned in this prior art solution that the shape imparted to the handle increases the user's comfort when gripping it.

While the provision of the shoulder portion, of the waist and of the enlarged end portion improves the user's grip and control over the brushing movements, this prior art solution leads to a handle that does not ergonomically adapt to the user's hands in the different operational conditions. The handle is also unnecessarily enlarged in regions in which the grip has only the function of directing the movements, as it occurs in the region of the shoulder portion. The alterations in the dimension of the cross section along the extension of the handle effectively produce means for retaining or locking the hands. Nevertheless, these retaining means are not designed for leading to a correct and comfortable positioning of the user's fingers around the handle, and for allowing a more precise control of the movements of the head of the toothbrush and, consequently, of the group of bristles.

Still in relation to the deficient adaptation of the user's fingers around the handle, the prior art solutions, which are provided with the shoulder portions, waist and enlarged free end, such as it occurs with that described in PCT/US96/12944, present the longitudinal extension of the handle developed according to a rectilinear alignment contained in a median plane, which is usually parallel to the mounting plane of the bristles to the head of the toothbrush. The rectilinear longitudinal development of the toothbrush does not always allow achieving a comfortable adaptation of the handle to the palm of the hand. Although the provision of localized shoulders and enlarged portions has the purpose of giving the handle the desired ergonomic characteristic, the simple existence of said elements has led to rather heavy designs, which impair the control and maneuverability of the toothbrush, that is, the acuity and precision of the movements to be imparted to the toothbrush during the brushing operation of the teeth. In brief, it may be said that the solutions proposed up to now have not succeeded in eliminating the need of providing a toothbrush with a more ergonomic handle, in order to give the user a better grip and more comfort during brushing, i.e., a better control in terms of acuity and precision of the movements.

OBJECTS OF THE INVENTION

By reason of the above mentioned deficiencies related to the known toothbrush handles, the present invention proposes a new construction for a toothbrush, with substantially improved ergonomic characteristics, giving the user more control over the movements to be effected, with the sensation of more comfort and safety when gripping the toothbrush, facilitating and motivating the act of brushing the teeth.

It is a more specific object of the present invention to provide a toothbrush as mentioned above, which allows the brushing operation to be achieved with more comfort, resulting from the correct positioning of the user's fingers, particularly the thumb, the little finger and the ring finger around the handle, as well as a better adaptation of the whole extension of the handle to the palm of the hand, in order to provide a better grip and a firm prehension of the handle, allowing to achieve levels of acuity and precision of the movements not reached before with the known toothbrushes.

SUMMARY OF THE INVENTION

In order to attain the objects mentioned above, basic ergonomic constructive improvements have been made in a toothbrush of the type comprising, usually in a single piece: a head, having a front face constructed to carry a group of bristles, which are developed in any adequate arrangement; an elongated handle, having a free end, an opposite end, a front face, and a rear face; and a neck, connecting the opposite end of the handle to the head. According to the invention, the handle comprises a first shoulder defining a thumb supporting front region and which is provided on the front face of the handle at its opposite end; a second shoulder, having opposite sides for supporting the little finger and the ring finger, respectively, and which is provided on the rear face of the handle, spaced from said handle, said first and second shoulders being used when the toothbrush is gripped with the bristles turned to the user; and a thumb supporting rear region, provided on the rear face of the handle, close to its opposite end, in order to be used when the toothbrush is gripped with the bristles turned away from the user. The handle has a cross section contour that increases, in a continuous or discontinuous way, from the thumb supporting front region, close to the first shoulder, to the second shoulder. The handle may be further provided with a curvature along the length thereof, in order to make the front face convex, and the rear face concave.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described below, with reference to the attached drawings, in which:

FIG. 1 is a lateral elevational view of a possible configuration for the toothbrush of the present invention, incorporating a head with no bristles in this illustration;

FIG. 2 is a top plan view of the toothbrush of FIG. 1, when observed from the side on which the bristles are mounted to the head.

FIG. 3 is a perspective view of a toothbrush formed with the handle illustrated in FIGS. 1 and 2, said handle being held by the user's hand in a first gripping condition, with the bristles facing the user;

FIG. 4 is a lateral elevational view of the toothbrush, further illustrating, schematically, the forces acting on the different parts of the handle when it is held in the first gripping condition illustrated in FIG. 3;

FIG. 5 is a perspective view similar to that of FIG. 3, but illustrating the toothbrush in a second gripping condition, in which the bristles are turned away from the user;

FIG. 6 is a lateral elevational view of the toothbrush, further illustrating, schematically, the forces acting on the different parts of the handle when it is held in the second gripping condition illustrated in FIG. 5; and

FIGS. 7 and 8 are similar views to those of FIGS. 1 and 2, but illustrating a second embodiment of the toothbrush.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

As illustrated in the drawings, the toothbrush of the present invention comprises, preferably molded in a single piece made of an adequate material, such as polypropylene, a head 10 with an adequate contour and having a front face 10 a, which is usually flat and constructed to receive and affix a group of bristles 20 and a rear face 10 b. The toothbrush further comprises an elongated handle 30, having a free end 31, an opposite end 32, a front face 30 a, and a rear face 30 b, the handle 30 being connected to the head 10 by means of a neck 40, which also has a front face 40 a and a rear face 40 b, and a longitudinal extension corresponding to about ¼ the length of the handle 30.

The handle 30, the neck 40, and the head 10 are preferably constructed symmetrically in relation to a median longitudinal plane P that intercepts the front and rear faces of these component parts of the toothbrush. The handle 30 comprises a first shoulder 33 defining a thumb supporting front region 33 a, which is incorporated to the front face 30 a of the handle 30, at the opposite end 32 of the latter and, more specifically, in the region where the handle 30 is joined to the neck 40. On the rear face 30 b of the handle 30, at the free end thereof, is formed a second shoulder 34, presenting two opposite sides for supporting the little finger and the ring finger, respectively, i.e., one finger on each side of the second shoulder 34.

As illustrated in FIG. 3, the first shoulder 33 and the second shoulder 34 are used when the toothbrush is gripped with the bristles 20 facing the user, said gripping being denominated herein as the first gripping condition.

According to the embodiment illustrated in FIGS. 1-6, the present toothbrush has the cross section contour of the handle 30 that increases continuously and progressively, from the thumb supporting front region 33 a, close to the first shoulder 33, to the second shoulder 34, when said cross section contour begins to suffer a progressive reduction, preferably by lateral contours, which are slightly curved in a convex way and match with the rounded free end 31 of the handle 30. In the first embodiment illustrated in FIGS. 1-6, the cross section of the handle 30, and not only its contour, increases continuously, from the thumb supporting front region 33 a to the second shoulder 34. Similarly, the thickness of the handle 30 is also progressively reduced, from the second shoulder 34, which is provided in a region spaced from the adjacent free end 31 of the handle 30, said thickness being reduced until the rounded free end 31 a of the handle 30 matches with the cross section contour of the handle in this region.

In the illustrated constructions, the width of the handle 30 progressively decreases, from the maximum width in the median region of the handle 30 to the free end 31, where said width has a value substantially equal to that of the region where the first shoulder 33 is provided.

Similarly, the cross section contour of the handle 30 is progressively reduced from its maximum value at the second shoulder 34, until reaching the free end 31 of the handle 30.

In the illustrated constructions, the handle is constructed to present a distance between the first shoulder 33 and the second shoulder 34 corresponding to about 70-90% the total length of the handle 30, the remaining of said length being completed by the distance of the second shoulder 34 to the free end 31.

As better illustrated in FIGS. 1, 4, 6 and 7, the handle 30 has a curvature that develops along the median longitudinal plane P, intercepting the front and rear faces 30 a and 30 b of the handle 30, in order to make convex said front face 30 a and concave said rear face 30 b.

The curvature of the rear face 30 b is made so as to define, at the opposite end 32 of the handle 30, a thumb supporting rear region 35 a, to be used when the toothbrush is gripped with the bristles 20 turned away from the user, as illustrated in FIG. 5, said gripping being denominated herein the second gripping condition.

In the embodiment illustrated in FIGS. 1-6, the first shoulder 33 and the second shoulder 34 have a width that is equal to the width of the region of the handle 30 where they are provided, said shoulders being defined by ramps matching with the respective front face 30 a and rear face 30 b, from which they project.

According to the longitudinal curvature imparted to the handle 30, its front face 30 a is defined by a convex arc, extending, with at least one radius of curvature, from the region of the first shoulder 33, to the free end 31 a of the handle 30. Similarly, the rear face 30 b of the handle 30 is defined by a concave arc, extending, with at least one radius of curvature, from the region of the first shoulder 33, where it defines the thumb supporting rear region 35 a, to the free end 31 of the handle 30.

In the embodiment illustrated in FIGS. 1-6, the rear face 30 b of the handle 30, between the second shoulder 34 and the free end 31, is in the form of a rear surface 30 c converging with the corresponding portion of the front face 30 a of the handle 30 and matching with the second shoulder 34, said rear surface 30 c being preferably shaped in a slightly convex way.

The construction of the handle described above allows that, in the first gripping condition illustrated in FIG. 3, the user's thumb be seated against the thumb supporting front region 33 a, close to the first shoulder 33, whereas the little and the ring fingers are seated on the rear face 30 b, close to the second shoulder 34, and the palm of the hand is pressed against the front face 30 a, in a convex arc, in the region of the latter close to the second shoulder 34, where both the thickness and the width of the handle 30 are larger. The correct positioning of the user's fingers, particularly his thumb in the region with the smallest cross section, allows for a more precise directional control of the movements to be imparted to the head 10 of the toothbrush during brushing. The thumb remains in an advanced position, anchored by the first shoulder 33, while the other fingers and the palm of the hand find a cross section of larger dimension, with the little finger and the ring finger of the user being each seated on one of the opposite sides of the second shoulder 34, assuring a better and safer prehension of the handle, giving firmness and comfort to the grip. The first and the second shoulders 33, 34 induce the user to correctly position his thumb, little finger, and ring finger, making difficult the improper use of the toothbrush.

In the second gripping condition illustrated in FIG. 5, the user's thumb is seated against the thumb supporting rear region 35 a, on the rear face 30 b of the handle 30, while the little and the ring fingers are seated against the front face 30 a, in a convex arc, of the handle 30, in the region of said front face 30 a with a larger cross section and where the latter becomes convergent in relation to the rear face 30 c of the free end 31 of the handle 30. In this second gripping condition, the little finger tends to embrace the rear face 30 b of the handle 30, close to the second shoulder 34, giving stability to the grip of the handle. The increase of the cross section has the effect of improving the prehension of the handle 30, as already mentioned in relation to the first gripping condition. It should be further observed that the thumb seated on the thumb supporting rear region 35 a also remains in an advanced position, facilitating to direct the movements to be imparted to the head 10, i.e., giving more acuity to the movements of the toothbrush.

Still according to the illustrated embodiments, the neck 40 has a width that decreases from a value equal to that of the width of the handle 30, at the adjacent region of the first shoulder 33, to a minimum value, at the region where it is connected to the head 10. The front face 40 a of the neck 40 matches with the first shoulder 33 by means of a concave matching surface 43, usually in the form of a cylindrical surface.

The neck 40 and the head 10 can present the rear faces 40 b and 10 b defined in the same convex surface that matches with the concave rear face 30 b of the handle 30 by means of the thumb supporting rear region 35 a, which is preferably offset from the first shoulder 33. Aiming at giving a more ergonomic characteristic to the toothbrush, the neck 40 and the head 10 can be provided according to a longitudinal direction, which forms, on the side of the front face 30 a of the handle 30, an obtuse angle in relation to the longitudinal direction of development of the handle 30, with the neck 30 and at least a certain extension of the handle 30, between the first and the second shoulders 33, 34, being laterally defined, in a plan view, by two rectilinear alignments that mutually converge to the direction of the head 10 and which are symmetrical in relation to the median longitudinal plane P.

The embodiment illustrated in FIGS. 7 and 8 is a variant from that described above and is firstly distinguished by the fact that the thumb supporting rear region 35 a is defined by a third shoulder 35 located opposite to the first shoulder 33 and defined by a ramp that matches with the rear face 30 b of the handle 30, from which it projects. The third shoulder 35 enhances the thumb supporting rear region 35 a.

In the embodiment of FIGS. 7 and 8, the handle now incorporates, in the region of the first and third shoulders 33, 35, a pair of first lateral shoulders 36, which are opposite to each other and slightly project from the contour of the handle 30, each first lateral shoulder 36 being defined by a pair of opposite ramps matching with each other and with the adjacent face of the handle 30, from which projects the respective first lateral shoulder 36.

This construction gives the handle 30 a lateral widening for both sides in the region of the first and the second shoulders 33, 35, further improving the comfort for both the seating of the fingers and the gripping on the handle 30 of the toothbrush.

In this constructive variant, the handle 30 further incorporates, on its rear face 30 b, a fourth shoulder 37, which maintains with the third shoulder 35 a spacing sufficient to adapt one of the user's fingers, either the forefinger or the thumb tip, upon gripping the handle 30 in the conditions illustrated in FIGS. 3, 4, 5 and 6.

As illustrated in FIGS. 7 and 8, the fourth shoulder 37 is defined by a pair of opposite ramps, matching with each other and with the rear face 30 b of the handle 30, on both sides of the fourth shoulder 37.

Aiming at further increasing the grip, the handle 30 can incorporate a pair of second lateral shoulders 38, opposite to each other and slightly projecting from the contour of the handle 30 in the region of the latter where is provided the fourth shoulder 37, each second lateral shoulder 38 being defined by a pair of opposite ramps, matching with each other and with the adjacent face of the handle 30, from which projects the respective second lateral shoulder 38.

As it can be noted, the constructive variant illustrated in FIGS. 7 and 8 provides a toothbrush, whose handle 30 still maintains a cross section contour that generally increases from the thumb supporting front region 33 a to the second shoulder 34, although said increase of the cross section contour is interrupted in the region where the fourth shoulder 37 and the second lateral shoulders 38 are provided.

Thus, while in both constructive forms the cross section contour of the handle 30 generally increases between the thumb supporting front region 33 a and the second shoulder 34, only in the first embodiment illustrated in FIGS. 1-6 said cross section contour increases continuously.

While only two embodiments of the present invention have been described and illustrated, it should be understood that alterations in the form of the constructions might be effected, without departing from the inventive concept defined in the claims that accompany the present disclosure. 

1. A toothbrush comprising a head (10), having a front face (10 a) constructed to carry a group of bristles (20): an elongated handle (30), having a free end (31), an opposite end (32), a front face (30 a), and a rear face (30 b); and a neck (40), connecting the opposite end (32) of the handle (30) to the head (10), characterized in that the handle (30) comprises a first shoulder (33) defining a thumb supporting front region (33 a) and which is provided on the front face (30 a) of the handle (30) at its opposite end (32); a second shoulder (34) having opposite sides for supporting the little finger and the ring finger, respectively, and which is provided on the rear face (30 b) of the handle (30) spaced from the free end (31) of the latter, said first and second shoulders (33, 34) being used when the toothbrush is gripped with the bristles (20) turned to the user; and a thumb supporting rear region (35 a) provided on the rear face (30 b) of the handle (30), close to its opposite end (32), in order to be used when the toothbrush is gripped with the bristles (20) turned away from the user, the handle (30) having a cross section contour that generally increases from the thumb supporting front region (33 a), close to the first shoulder (33), to the second shoulder (34).
 2. Toothbrush, according to claim 1, characterized in that the first and second shoulders (33, 34) are defined by ramps matching with the respective front face (30 a) and rear face (30 b) of the handle (30), from which said shoulders project.
 3. Toothbrush, according to claim 1, characterized in that the width of the handle (30) decreases progressively, from the maximum width in the second shoulder (34), to the free end (31), where it has a value substantially equal to that of the region in which the first shoulder (33) is provided.
 4. Toothbrush, according to claim 3, characterized in that the free end (31) of the handle (30) is rounded and matches with the cross section contour of the handle (30) in this region.
 5. Toothbrush, according to claim 1, characterized in that the cross section contour of the handle (30) is progressively reduced, from its maximum value at the second shoulder (34), until reaching the free end (31) of the handle (30).
 6. Toothbrush, according to claim 1, characterized in that the distance between the first shoulder (33) and the second shoulder (34) corresponds to about 70-90% the length of the handle (30).
 7. Toothbrush, according to claim 1, characterized in that the handle (30) has a curvature along a longitudinal median plane (P) intercepting the front face (30 a) and rear face (30 b) of the handle (30), in order to make convex the front face (30 a) and concave the rear face (30 b).
 8. Toothbrush, according to claim 7, characterized in that said thumb supporting rear region (35 a) is defined by the curvature of the rear face (30 b) close to the opposite end (32) of the handle (30).
 9. Toothbrush, according to claim 7, characterized in that the thumb supporting rear region (35 a) is defined by a third shoulder (35) opposite to the first shoulder (33).
 10. Toothbrush, according to claim 9, characterized in that the third shoulder (35) is defined by a ramp matching with the rear face (30 b) of the handle (30) from which it projects.
 11. Toothbrush, according to claim 9, characterized in that the handle (30) incorporates, in the region of the first and third shoulders (33, 35), a pair of first lateral shoulders (36), which are opposite to each other and slightly project from the contour of the handle (30), each first lateral shoulder (36) being defined by a pair of opposite ramps matching with each other and with the adjacent face of the handle (30), from which projects the respective first lateral shoulder (36).
 12. Toothbrush, according to claim 9, characterized in that the handle (30) incorporates, on its rear face (30 b), a fourth shoulder (37), which maintains with the third shoulder (35) a spacing sufficient to adapt one of the user's fingers, upon gripping the handle (30).
 13. Toothbrush, according to claim 12, characterized in that the fourth shoulder (37) is defined by a pair of opposite ramps, matching with each other and with the rear face (30 b) of the handle (30), on both sides of the fourth shoulder (37).
 14. Toothbrush, according to claim 12, characterized in that the handle (30) incorporates a pair of second lateral shoulders (38), opposite to each other and slightly projecting from the contour of the handle (30) in the region of the latter where is provided the fourth shoulder (37).
 15. Toothbrush, according to claim 14, characterized in that each second lateral shoulder (38) is defined by a pair of opposite ramps, matching with each other and with the adjacent face of the handle (30), from which projects the respective second lateral shoulder (38).
 16. Toothbrush, according to claim 7, characterized in that the front face (30 a) of the handle (30) extends in a convex arc, with at least one radius of curvature, from the thumb supporting front region (33 a), close to the first shoulder (33), to the free end (31) of the handle (30).
 17. Toothbrush, according to claim 12, characterized in that the rear face (30 b) of the handle (30), between the second shoulder (34) and the free end (31), is in the form of a rear surface (30 c) converging with the corresponding portion of the front face (30 a) of the handle (30) and matching with the second shoulder (34).
 18. Toothbrush, according to claim 13, characterized in that the rear surface (30 c) is slightly convex.
 19. Toothbrush, according to claim 7, characterized in that the median longitudinal plane (P) is a plane of symmetry of the handle (30), of the neck (40) and of the head (10).
 20. Toothbrush, according to claim 7, characterized in that the rear face (30 b) of the handle (30) is defined by a concave arc extending, with at least one radius of curvature, from the thumb supporting front region (33 a), close to the first shoulder (33), where it defines the thumb supporting rear region (35 a), to a region spaced from the free end (31) of the handle (30), where it defines the second shoulder (34).
 21. Toothbrush, according to claim 7, characterized in that the width of the neck (40) decreases from a value that is equal to the width of the handle (30), at the adjacent thumb supporting front region (33 a), close to the first shoulder (33), to a minimum value, at the region in which it is joined to the head (10).
 22. Toothbrush, according to claim 7, characterized in that the neck (40) and the head (10) have a rear face (40 b, 10 b) defined by a convex surface matching with the concave rear face (30 b) of the handle (30) by means of the thumb supporting rear region (35 a) located slightly offset from the first shoulder (33).
 23. Toothbrush, according to claim 12, characterized in that the neck (40) and the head (10) are provided according to a longitudinal direction, which forms, on the side of the front face (30 a) of the handle (30), an obtuse angle in relation to the longitudinal direction of development of the handle (30).
 24. Toothbrush, according to claim 17, characterized in that the neck (40) and at least a certain extension of the handle (30), between the first shoulder (33) and the second shoulder (34), present a lateral contour defined by two rectilinear alignments, mutually converging to the direction of the head (10) and which are symmetrical in relation to the median longitudinal plane (P).
 25. Toothbrush, according to claim 1, characterized in that the neck (40) has a front face (40 a) matching with the first shoulder (33) by means of a concave matching surface (43).
 26. Toothbrush, according to claim 1, characterized in that the cross section of the handle (30) presents a contour that increases continuously and progressively from the thumb supporting front region (33 a), close to the first shoulder (33), to the second shoulder (34).
 27. Toothbrush, according to claim 26, characterized in that the first and the second shoulders (33, 34) present a width that is equal to the width of the region of the handle (30) in which they are provided.
 28. Toothbrush, according to claim 26, characterized in that the handle (30) has a cross section that increases continuously from the thumb supporting front region (33 a) to the second shoulder (34). 